TDI Advanced Wreck

[tmassey]

I cannot understand how strobes placed in the wreck at such a distance that a siltout would certainly prevent the wreck diver from seeing from one strobe to the other strobe is a better idea and safer than running a proper line. It defies logic.

I'm not speaking for anyone, especially John Chatterton. But one reason is time. It's just faster and easier to drop strobes than run a line.

This kind of comes back to the thing I've been talking about a lot in my reviews: whether something is "better" or "worse" depends on your initial foundational assumptions. If you weigh safety as very high, to the intentional (and possibly desirable!) exclusion of other factors, you will no doubt end up with a very safe way of diving -- that might also limit what you can actually accomplish. Whereas if you weigh effectiveness as very high, you may (intentionally!) lower the amount of available safety in order to gain additional capability.

Again, there's lots of wiggle room there: how *much* safety do you reduce, for how *much* capability you gain. And intelligent and reasonable people can differ in their evaluations.

And yes, you can argue for both sides of this. "Need more time? Bring more gas!" "But I could instead use that extra gas for more capability instead of more safety I do not feel is necessary!" "But if you think that way, why dive thirds? Just dive until you're empty!" "Because that level of safety *is* necessary!" And now we're simply arguing about what the word "necessary" means to each party.

Which is a long-winded way of trying to short-circuit an argument about lines vs. strobes. And like @kensuf stated above, it's not even an all-or-nothing thing, but an array of tools in the toolbox. I mean, do we run lines in swim-throughs? It's not like the line between "no line needed" and "run a line" is exactly agreed-upon, either.

ETA: Nope. Looks like in the time it took to write my reply, we are full-on in an argument about lines vs. strobes. Oh well...

 

[Manatee Diver]

Again, there's lots of wiggle room there: how *much* safety do you reduce, for how *much* capability you gain. And intelligent and reasonable people can differ in their evaluations.

Which is what I was trying to convey in the comment. I feel that for most cave divers the default mindset would be safety over capability. If the dive plan is iffy you throw in an extra bottle, or do a prep dive and place a safety bottle. Added risk that can easily be mitigated, should be mitigated.

 

[Jim Lapenta]

I recall reading about guys doing "Progressive Penetration" on the Andrea Doria. Am I mistaken on that?

Nope, you are not mistaken.
When Gary Gentile and those guys started doing the Doria progressive penetration was the rule. Running a line on the outside from the downline to a hole was ok. After that, nope.
The more radical ones would threaten to cut lines if someone ran them inside.
They considered them adding an entanglement hazard. And it wasn't 25-35 ft at a time. It could be as little as 5 or ten. Or just sticking your head in an opening and memorizing the layout of the space. Then going back to surface, document it, and the next dive you got to go in. Maybe.
Most of the dives on the Doria and other wrecks they did were solo. Looking for china and other artifacts. Some got very protective over their honey holes. Another reason they didn't want lines run. Could lead someone to their spot.
I met Gary and had a chance to talk to him around 2007-2008 and the way they did things early on when diving the Doria makes one wonder why so many more didn't die on it.
Not only were they doing progressive penetration but they were, most of the time, doing it on air and narced as hell.

 

[kensuf]

I guess my thinking is: Why not just run a line"?

As I've said, we did on every wreck in the class except one, the RSB-1. When we dove the RSB-1 it was made clear that it was a good example of a place where you could just use strobes only.

I recall reading about guys doing "Progressive Penetration" on the Andrea Doria. Am I mistaken on that?

I recall reading a lot about guys doing "Deep Air" on the Andrea Doria too. I don't think anyone advocates either method on a dive like the Doria.

I guess I'm missing the point you're trying to make.

 

[Capt Jim Wyatt]

I guess I'm missing the point you're trying to make.

The point is to run a line.

 

[kensuf]

The point is to run a line.

I don't disagree. And as I've stated before, that was done in the class.

 

[Capt Jim Wyatt]

I don't disagree. And as I've stated before, that was done in the class.

Yea I got that a few posts ago.

I was simply pointing out to others that one should run a line. The title of the thread is Advanced Wreck and my thinking is this happens in the bowels of a shipwreck where there is heavy silt and little if any flow to clear the silt out. Thus a line and not a light is the safest way to exit in low/zero vis.
I am not sure how to respond to anyone who posits that it may be acceptable to increase risk in order to save time other than to say "nuts".

 

[lostsheep]

One of the explicit examples I recall is the U869. Do you need a line in a submarine? Can you memorize and then feel your way through a tube? Would a line be faster than memorized progressive penetration with strobes? In this instance the size of the restrictions added complications for gas reserves; did omitting the line load share risk between getting lost vs time?

I don't have the answers to the above questions.

I am not going anywhere near the U869 but I think we would all agree that is an advanced (actual non-sterilized) wreck.

EDIT: I'll back off now, I didn't mean to hijack this thread

 

[Manatee Diver]

EDIT: I'll back off now, I didn't mean to hijack this thread

It is my thread, I say go for it.

 

[lermontov]

So I scooped up the Advanced Wreck book that @Marie13 had up. Does TDI really think this pamphlet is worth $40?

Is it not that good? I was planning on buying it myself as a reference book. I was hoping it was like the Cavern and Cave textbooks they produced.

A buddy of mine has rewritten his own Advanced wreck guide out of sheer frustration of having to use the TDI book, lots of errors and confusing questions, gas calculation errors etc drop him a line - info@godivepacific.nz he may send you a digital copy if you ask nicely. @DiveClimbRide is on this board -he works for him